Scientific illumination for schools / Holophane Limited.

Date:
1921
Catalogue details

Licence: Public Domain Mark

Credit: Scientific illumination for schools / Holophane Limited. Source: Wellcome Collection.

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    Why Good Lighting is Important. The number of school children in this country is several millions. Statistics show that of this number a substantial percentage has defective vision, and that this percentage tends to increase with the older classes. This increasing proportion of those with bad eyesight may be traced to a considerable extent to the way in which the eyes are used in the every-day work in the schoolroom, and is largely due to the conditions which surround vision. The school- room lighting is one of these important conditions. Amongst the most important points which require consideration and treatment to ensure good lighting are (1) avoidance of glare whether from the lamps used or from the blackboard, (2) intensities of illumination which vary according to the class of work for which a particular room is intended to be used, and (3) the correct planning of the points of the lamps so that an even distribution of the light over the working plane is obtained when the proper reflectors are used. There are also other points which can materially assist good illumination, all of which are treated in this booklet. ‘Reducing Glare. The increasing brilliancy of modern lamps is becoming more and more a menace to eyesight. The new gas-filled lamp, although it possesses the great advantage of high efficiency, has the highly objectionable feature of excessive brilliancy. Unless the eyes of those in the room are adequately protected from its glare, permanent injury to eyesight may result from this cause. The contrast of the great brilliancy of this new lamp with older types of lamps is very marked. Glare from Blackboard. Nearly everyone has experienced a disagreeable effect when looking at a blackboard owing to the sheen of reflected light directed towards the eyes. In artificial ight, as well as in daylight, this reflection from blackboard surfaces is objectionable. To avoid this care should be taken to keep the surface of the boards a dull finish, and to place the lamp in such a position as to obviate this objection. It may be necessary in some cases to provide special blackboard lamps for minimising the glare or sheen effect, and in new buildings there is some choice in the original position of the boards with
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